Method and Apparatus for Privacy-Enhanced Evidence Evaluation

1. A method, comprising: sending, by a requesting node and to a first network entity, a request for pre-evaluation information regarding evidence data of a target object, wherein the evidence data comprises knowledge related to the target object, and wherein the target object comprises a networking node configured to communicate with the requesting node; in response to successful verification of the requesting node at a second network entity, obtaining, by the requesting node and from the first network entity, the pre-evaluation information, the pre-evaluation information comprising re-encrypted evidence data of the target object associated with one or more time slots; and calculating, by the requesting node with a private key of the requesting node, an evidence evaluation of the target object based at least in part on one of the pre-evaluation information, a local evidence record of the target object at the requesting node, and statistical information obtained from the first network entity for at least one of the one or more time slots; wherein the re-encrypted evidence data at an associated time slot results at least in part from encrypted evidence data of the target object collected by the first network entity from one or more evidence providers at the associated time slot, by at least using a re-encryption key from the second network entity, and wherein the statistical information indicates a quantity of the one or more evidence providers from which the encrypted evidence data is collected.

2. The method according to claim 1 , wherein the one or more evidence providers comprise the requesting node.

3. The method according to claim 1 , wherein the encrypted evidence data of the target object collected from a corresponding evidence provider at the associated time slot comprises the encrypted evidence data of the target object by the corresponding evidence provider using an encryption key from the second network entity.

4. The method according to claim 1 , wherein the encrypted evidence data of the target object collected from the one or more evidence providers at the associated time slot is processed at the first network entity based at least in part on a homomorphic encryption scheme.

5. The method according to claim 1 , wherein the re-encrypted evidence data of the target object at the associated time slot comprises the encrypted evidence data of the target object at the associated time slot by using a public key of the requesting node.

6. The method according to claim 1 , wherein the evidence evaluation of the target object is calculated by at least: decrypting the re-encrypted evidence data of the target object by using the private key of the requesting node; and estimating the evidence evaluation of the target object based at least in part on a decryption result of the re-encrypted evidence data of the target object.

7. The method according to claim 1 , wherein the request for the pre-evaluation information comprises a credential for verifying the requesting node.

8. An apparatus, comprising: at least one processor; and at least one memory comprising computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to: send, to a first network entity, a request for pre-evaluation information regarding evidence data of a target object, wherein the evidence data comprises knowledge related to the target object, and wherein the target object comprises a networking node configured to communicate with the apparatus; obtain, from the first network entity and in response to successful verification of the apparatus at a second network entity, the pre-evaluation information, the pre-evaluation information comprising re-encrypted evidence data of the target object associated with one or more time slots; and calculate, with a private key of the apparatus, an evidence evaluation of the target object based at least in part on one of the pre-evaluation information, a local evidence record of the target object at the apparatus, and statistical information obtained from the first network entity for at least one of the one or more time slots; wherein the re-encrypted evidence data at an associated time slot results at least in part from encrypted evidence data of the target object collected by the first network entity from one or more evidence providers at the associated time slot, by using a re-encryption key from the second network entity, and wherein the statistical information indicates a quantity of the one or more evidence providers from which the encrypted evidence data is collected.

9. The apparatus according to claim 8 , wherein the one or more evidence providers comprise the apparatus.

10. The apparatus according to claim 8 , wherein the encrypted evidence data of the target object collected from a corresponding evidence provider at the associated time slot comprises the encrypted evidence data of the target object by the corresponding evidence provider using an encryption key from the second network entity.

11. The apparatus according to claim 8 , wherein the encrypted evidence data of the target object collected from the one or more evidence providers at the associated time slot is processed at the first network entity based at least in part on a homomorphic encryption scheme.

12. The apparatus according to claim 8 , wherein the re-encrypted evidence data of the target object at the associated time slot comprises the encrypted evidence data of the target object at the associated time slot by using a public key of the apparatus.

13. The apparatus according to claim 8 , wherein the evidence evaluation of the target object is calculated by at least: decrypting the re-encrypted evidence data of the target object by using the private key of the apparatus; and estimating the evidence evaluation of the target object based at least in part on a decryption result of the re-encrypted evidence data of the target object.

14. The apparatus according to claim 8 , wherein the request for the pre-evaluation information comprises a credential for verifying the apparatus.